Caribbean hermit crabs are both herbivorous and scavengers. In the wild, C. clypeatus feeds on animal and plant remains, overripe fruit, and feces of other animals,[3] including the Mona ground iguana, Cyclura stejnegeri.[2] The West Indian top snail (Cittarium pica) shell is often used for its home, and the hermit crab can use its larger claw to cover the aperture of the shell for protection against predators.[3] Typically, the Caribbean hermit crab's left claw is larger in size than its right claw and is purple in color. Female land hermit crabs release fertilized eggs into the ocean. The spawning (called "washing" in the English-speaking Caribbean) occurs on certain nights, usually around August.[2]

This species is one of the two land hermit crabs commonly sold in the United States as a pet, the other being the Ecuadorian hermit crab.[4][5]